Materials Data on ErAgS2 by Materials Project

Abstract

ErAgS2 crystallizes in the tetragonal I4_1md space group. The structure is three-dimensional. Er3+ is bonded to six S2- atoms to form ErS6 octahedra that share corners with four equivalent ErS6 octahedra, corners with three equivalent AgS5 trigonal bipyramids, edges with four equivalent ErS6 octahedra, and edges with six equivalent AgS5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 10–13°. There are a spread of Er–S bond distances ranging from 2.70–2.76 Å. Ag1+ is bonded to five S2- atoms to form distorted AgS5 trigonal bipyramids that share corners with three equivalent ErS6 octahedra, corners with eight equivalent AgS5 trigonal bipyramids, and edges with six equivalent ErS6 octahedra. The corner-sharing octahedra tilt angles range from 0–76°. There are a spread of Ag–S bond distances ranging from 2.70–2.84 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Er3+ and three equivalent Ag1+ atoms to form SEr3Ag3 octahedra that share corners with four equivalent SEr3Ag3 octahedra, corners with three equivalent SEr3Ag2 trigonal bipyramids, edges with four equivalent SEr3Ag3 octahedra, and edges with six equivalent SEr3Ag2 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 7–10°. In the second S2- site, S2- is bonded to three equivalent Er3+ and two equivalent Ag1+ atoms to form distorted SEr3Ag2 trigonal bipyramids that share corners with three equivalent SEr3Ag3 octahedra, corners with eight equivalent SEr3Ag2 trigonal bipyramids, and edges with six equivalent SEr3Ag3 octahedra. The corner-sharing octahedra tilt angles range from 0–76°.